Luminosity Monitoring For Prim Ex Dan Dale Prim
- Slides: 11
Luminosity Monitoring For Prim. Ex Dan Dale Prim. Ex Collaboration Meeting February 23, 2007
E. P. point 14 • “Electron counting systematics listed as 0. 8%. How did you get this number? ” Electron Counting Systematics 0. 8% discrepancy between CLOCK and OUT-OF-TIME methods
E. P. point 15 • “You discuss in the Appendix effects of beam intensity instabilities on rate sampling. You don’t quantify this effect and do not include in final error” 0. 8% discrepancy between CLOCK and OUT-OF-TIME methods CLOCK trigger sampling used -> insensitive to beam instabilities
Point 11: Clock frequency, window width • Ne = ne / (W x ntrigs) Live 1 • Clock frequency = 195. 3125 +-0. 020 k. Hz • W = 7 microseconds – integral linearity < 25 ppm differential linearity 100 psec
DS point: Different PS dipole settings--run 4339 collimator 0. 1 “ off
Effect of Collimator Position on Tagging Ratios
Effect of Collimator Position on Tagging Ratios – units are inches
TAC losses 0. 1% interact in vacuum window & Helium – overwhelmingly pair production
Point 13: “Section 25 all numbers in two tables identical except last one. Something is not right” Luminosity Error Budget ____________________ effect error(%) Uncorrected leakage current 0. 5 (1. 4%/3) TAC statistics 0. 2 (0. 5 per T channel) Electron counting systematics 0. 8 (clock versus out of time) Electron counting statistics negligible TAC reproducibility 0. 4 HYCAL collimation of TAC 0. 25 (worst case, no photon collimator) Beam position/collimator effect 0. 2 Absorption in TAC runs not yet evaluated ________________________________ 1. 1%
What we can ultimately do. Luminosity Error Budget ____________________ effect error(%) Corrected leakage current 0. 3 (1. 4%/3/2) TAC statistics 0. 2 (0. 5 per T channel) electron counting systematics 0. 8 (clock versus out of time) Electron counting statistics negligible TAC reproducibility 0. 4 HYCAL collimation of TAC 0. 25 (worst case, no photon collimator) Beam position/collimator effect 0. 2 Absorption in TAC runs not yet evaluated ________________________________ 1. 0%
• Points 1, 3: “Please define meaning of Tcounter and T channel” • Point 2, 16: “In section 4 (2002 run analysis) just T counters used. E-T coincides since implemented. Needs to be written up. • Point 5: absolute efficiency of TAC – dedicated run? ?
